Description

The high and low pressure switch is designed to be easy to use, and the high voltage can be turned off without load ; Current monitoring, mainly displays the 300B screen current, so as to check the 300B aging status.
The vaccum tube holder adopts a shock-absorbing structure to prevent the electronic tube filament from shock by external forces ; Fully manual symmetrical configuration, including voltage stabilizing circuit e.2.0 Pure iron paint cabinet for effective anti-interference against magnetic field generated by transconductance transformer.
300b used the early simple pentode one-stage drive, and the gain is not as large as some combined or two-stage and three-stage drive. But the first-level advantage is that the pure class a amplifier can be matched with different external pre-amplifiers without excessive microphone effects, self-excitation and low-frequency noise caused by excessive gain. In the absence of a preamp, you can really hear different types of 300b real sounds.
Everyone knows that the direct heating tube is characterized by a strong human voice/mid-range sound and a thick and warm voice. However, different types of direct heating tubes have different sounds in the high and low frequency bands. However, the most prominent feature of 300B is the human voice. Many of my friends do 300B because of improper circuit application and the use of cheap transformers. This makes the high and low frequency bands of 300B even more lacking.
This product uses the early 300B circuit and uses a 5-pole tube EF37 as the driving stage, which makes the sound more lively and the sound field is wider. It has an absolute advantage over ordinary dual triodes. In terms of low frequency, this machine uses a 30W output transformer, and the volume sense is even better than the indirect heat pipe of the same power. The capacitance matched with each other according to the sound characteristics to make the sound more comfortable, clean and durable